Reactor, plant and industrial process for the continuous preparation of high-purity silicon tetrachloride or high-purity germanium tetrachloride

Abstract

A reactor, a plant, and a continuous, industrial process carried out therein for preparing high-purity silicon tetrachloride or high-purity germanium tetrachloride by treating the silicon tetrachloride or germanium tetrachloride to be purified, which is contaminated by at least one hydrogen-containing compound, by a cold plasma and isolating purified high-purity silicon tetrachloride or germanium tetrachloride from the resulting treated phase by fractional distillation. The treatment is carried out in a plasma reactor in which longitudinal axes of a dielectric, of a high-voltage electrode, and of a grounded, metallic heat exchanger are oriented parallel to one another and at the same time parallel to the force vector of gravity.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is the National Stage of PCT / EP06 / 62916, filed Jun. 6, 2006, the disclosure of which is incorporated herein by reference in its entirety. The parent application claims priority to German Application No. 10 2005 041 137.1 files Aug. 30, 2005, the disclosure of which is incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION[0002]The present invention relates to a continuous process, a plant and a reactor for the preparation of high-purity silicon tetrachloride or high-purity germanium tetrachloride by treatment of the silicon tetrachloride or germanium tetrachloride to be purified, which is contaminated with at least one hydrogen-containing compound, by means of a cold plasma and subsequent fractional distillation of the treated phase.[0003]Silicon tetrachloride (SiCl4) and germanium tetrachloride (GeCl4) are used, inter alia, for producing optical fibres. For these applications, SiCl4 having a very hi...

AI Technical Summary

Benefits of technology

[0011]It is an object of the present invention to provide a further possible way of carrying out a continuous process for the preparation of high-purity silicon tetrachloride or high-purity germanium tetrachloride by treatment of the silicon tetrachloride or germanium tetrachloride to be purified by means of a cold plasma on an industrial scale.

Problems solved by technology

Here, hydrogen-containing compounds are a considerable disadvantage, even if they are present in only ppm amounts.

A substantial disadvantage of this process is that the plant components come into contact with chlorine gas, which is added in considerable amounts according to EP 0 488 765 A1, and are thus subjected to particularly severe corrosion, which inevitably leads to frequent shutdowns of the plant.

Both result in high operating costs for the plant.

A further particular disadvantage is the particularly poor energy efficiency of UV radiation sources proposed, for example, by EP 0 488 765 A1.

This results in particularly long treatment times, which likewise leads to high costs.

A particular disadvantage of this process is the fact that a reducing agent has to be added.

Furthermore, suitable spacers are only moderately resistant to SiCl4 or GeCl4.

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